There is an ongoing search for precursors for deposition of metal containing films on various substrates. Metal containing films are used, for example, in gate dielectrics, capacitor dielectrics, electrode layers, seed layers and for many other functions in integrated circuit devices and microelectronic devices. Many precursors are known for vapor deposition of metal containing films, but new precursors are needed to improve precursor delivery process, for example to reduce clogging of the delivery lines and to reduce the formation of unwanted particles on the wafers, to increase deposition rate and deposition temperature and/or to improve the desired properties of metal containing films. For example, there is still a need to develop new Group 4 precursors, preferably liquid Group 4 precursors, which exhibit at least one of the following properties: lower molecular weight (e.g., 550 m.u. or below), lower melting point (e.g., 100° C. or below), and higher vapor pressure (e.g., 0.5 torr or greater at temperature less than 200° C.).
The following references are in the field of precursors for deposition of metal containing films and metal complexes containing amidate ligands.
“Development of a new class of copper(II) precursors for use in atomic layer deposition film growth”; Karunarathne, Mahesh C.; Heeg, Mary Jane; Winter, Charles H.; Abstracts of Papers, 236th ACS National Meeting, Philadelphia, Pa., United States, Aug. 17-21, 2008 (2008), INOR-553; Publisher: American Chemical Society, Washington, D.C.
“N,O-Chelates of Group 4 Metals: Contrasting the Use of Amidates and Ureates in the Synthesis of Metal Dichlorides”; Leitch, David C.; Beard, J. David; Thomson, Robert K.; Wright, Vincent A.; Patrick, Brian O.; Schafer, Laurel L Vancouver, European Journal of Inorganic Chemistry (2009), (18), pp 2691-2701.
“An Easy-To-Use, Regioselective, And Robust Bis(Amidate) Titanium Hydroamination Precatalyst: Mechanistic And Synthetic Investigations Toward The Preparation Of Tetrahydroisoquinolines And Benzoquinolizine Alkaloids”; Zhang, Zhe; Leitch, David C.; Lu, Man; Patrick, Brian O.; Schafer, Laurel L Vancouver, Chemistry—A European Journal (2007), 13 (7), pp 2012-2022.
“A Pentagonal Pyramidal Zirconium Imido Complex for Catalytic Hydroamination of Unactivated Alkenes”; Thomson, Robert K.; Bexrud, Jason A.; Schafer, Laurel L.; Organometallics (2006), 25 (17), pp 4069-4071
“Structure, Bonding, and Reactivity of Ti and Zr Amidate Complexes: DFT and X-Ray Crystallographic Studies”; Thomson, Robert K.; Zahariev, Federico E.; Zhang, Zhe; Patrick, Brian O.; Wang, Yan Alexander; Schafer, Laurel L.; Inorganic Chemistry (2005), 44 (24), pp 8680-8689.
“Amidate complexes of titanium and zirconium: a new class of tunable precatalysts for the hydroamination of alkynes”; Li, Chunyu; Thomson, Robert K.; Gillon, Bronwyn; Patrick, Brian O.; Schafer, Laurel L.; Chemical Communications (Cambridge, United Kingdom) (2003), (19), pp 2462-2463.
“Bis- and mono(amidate) complexes of yttrium: Synthesis, characterization, and use as precatalysts for the hydroamination of aminoalkenes.”; Stanlake, L. J. E. and L. L. Schafer (2009). Organometallics 28 (14): pp 3990-3998.
“Tantalum-amidate complexes for the hydroaminoalkylation of secondary amines: enhanced substrate scope and enantioselective chiral amine synthesis”; Eisenberger, P., R. O. Ayinla, J. M. P. Lauzon and L. L. Schafer (2009). Angewandte Chemie—International Edition 48 (44): pp 8361-8365.
“Rare-earth amidate complexes. Easily accessed initiators for μ-caprolactone ring-opening polymerization”; Stanlake, L. J. E., J. D. Beard and L. L. Schafer (2008). Inorganic Chemistry 47 (18): pp 8062-8068.
“Synthesis and structure of a linked-bis(amidate) ligand and some complexes with titanium”; Giesbrecht, G. R., A. Shafir and J. Arnold (2001). Inorganic Chemistry 40 (23): pp 6069-6072.